abstract |
Provided are a compound as represented by formula (D) and a preparation method therefor, where X<sub>2</sub> is a halogen, Pg is selected from H and an amino protecting group, such as Cbz, Boc, Fmoc, Alloc, Teoc, methoxycarbonyl or ethoxycarbonyl. Also provided are a synthesized intermediate compound of the formula (D) compound and a preparation method for the intermediate compound. |